using Tremulous art assets that the creators of Murnatan are not allowed to use.
We are already well aware of this.
1. - The project has not yet reached commercial state, has not been marketed to an audience, has not earned a dollar, and thus has not violated the original CC-BY-SA.
2. - The only potentially conflicting content currently in this game is on the cover page of the website.
3. - I can guarantee you that Rotacak is already smart enough to know that the art assets on the cover page need to be changed before release, and is probably already planning to do so, but has been more concerned about finishing the damn game first,
along with the assets to create new cover art in the process.
4. - Plush Grangers are being sold at-cost with little to no profit, because Rotacak needs a way to get them loving homes other than their originally intended use as Kickstarter rewards. Rotacak needs office space to work in, and that's problematic with 50 adorable plushies sitting on his desk.
If you
still have a problem, then file a motion in court. You will loose, and succeed in nothing other than wasting your own money and
possibly forcing Rota to change the art a few months earlier.